1. Field of the Invention
The present invention relates generally to a plastic pipe scraper, and more particularly, to apparatus for scraping selected portions of the external surfaces of plastic pipe.
2. Description of the Prior Art
Plastic pipe systems comprised of plastic pipe sections connected to plastic pipe fittings such as couplings, tees and elbows have been used for a variety of purposes heretofore, e.g., the domestic distribution of natural gas. In such systems, the pipe sections and fittings are often fused or welded together by the application of electric heat thereto. That is, electric resistance heating elements are provided in the plastic pipe fittings adjacent the inside surfaces thereof and when the plastic pipe systems are constructed, the inside surfaces of the fittings are welded to adjacent outside surfaces of plastic pipe sections by applying electric power to the resistance heating elements of the fittings. The heating element of, for example, a sleeve, heats the inside surface of the sleeve and the outside surface of the end of a plastic pipe section positioned within the sleeve to a temperature level which causes the thermoplastic materials of the sleeve and pipe section to be fused or welded together. Examples of electric heat weldable thermoplastic fittings are those described in U.S. Pat. Nos. 4,147,926, issued Apr. 3, 1979, and 4,349,219, issued Sept. 14, 1982.
It has been found that in order to insure that good welds are formed between plastic pipe sections and electrically weldable plastic pipe fittings, the portions of the outside surfaces of the plastic pipe sections to be welded to the fittings must be scraped whereby the oxidized outer film of plastic material is removed therefrom. While various plastic pipe scraper apparatus have been developed and used for this purpose heretofore, such apparatus have been difficult to use, have often caused gouges to be formed in the pipe and have generally proven to be unsatisfactory. Thus, there is a need for a plastic pipe scraper which can be efficiently utilized to scrape selected portions of the external surfaces of plastic pipe sections.